By way of background, it has been found that the best apple cider is made by pressing relatively thin layers of apple pomace, the pomace having been wrapped in cloth which is placed between adjacent press racks or press plates. Prior to the development of U.S. Pat. No. 4,892,665 this procedure was extremely labor-intensive because each layer had to be initially wrapped in a separate cloth and then placed between racks for pressing, and after pressing the cloth had to be unwrapped manually to dispose of the pomace residue, which is called press cake. The cider press shown in U.S. Pat. No. 4,892,665, (which was developed by the applicant of the present invention) was designed to overcome the foregoing disadvantages. This prior art cider press has a centrally located moveable platen and fixed platens to either side. A plurality of press racks or plates are disposed between the platens, the racks in turn being supported by a scissor linkage. When the moveable platen moves towards or away from a fixed platen it causes corresponding movement of the scissor linkage, the scissor linkage in turn causing corresponding movement of the press racks. Filter bags are supported by and between adjacent racks. When the racks are moved to their spaced apart position, the open filter bags are filled with the fruit which is to be pressed. Then the moveable platen will be moved toward the fixed platen, causing the scissor linkage to cause corresponding movement of the racks, which will in turn press the fruit within the filter bags. At the completion of the pressing operation the movable platen will be moved back to its open position. With this design it is not necessary to close the top of the press bags during pressing.
In order to avoid undue stress on the scissor linkage of the design shown in the foregoing patent, the fruit which is to be pressed should be evenly distributed within each press section, each filter bag receiving about the same amount of fruit, and the fruit within each filter bag being evenly distributed from side to side. If this even distribution does not occur, or if each bag does not receive the same amount of fruit, it has been found that the pressing forces may have to be borne by the adjacent scissor linkage, causing undue stress on the linkage. This requires that the scissor linkage be designed to withstand the press forces. For example, when a filter bag is not filled and it is next to a filter bag that is completely filled, the press forces for the empty filter bag must be borne by the adjacent scissor linkage, as there is no fruit within the empty filter bag to absorb the press forces. As the scissor linkage must have sufficient strength to withstand maximum press forces, it has been necessary to make the links of the scissors linkage of relatively thick bar stock. Because of this, it had been found that the scissor links will contact each other before the press racks do, thus restricting the pressing operation when the filter bags are not filled with the proper amount of material.
It has also been found when using the design of the forgoing patent, that if the fruit to be pressed is soft and mushy that the press racks may move from side to side causing undue stress upon the machine. It is also been found in the prior machine, that there are additional structural requirements due to the lifting of the filter bags and all of the associated structure as the filter bags are moved from their normal working position to an inverted position to one side of the machine.
Other forms of presses are known which carry material receiving a plurality of containers. One such design is shown in U.S. Pat. No. 424,543 which is designed for pressing oil from cotton seed or the like. This design includes a plurality of press boxes supported by guide rods on each side of the press boxes, each press box including it own plunger. The design shown in this patent requires the use of press boxes which must be closed prior to pressing, which cannot be readily removed from the machine for cleaning, and which also requires that the press cake be ejected upwardly at the completion of the pressing operation.
Other prior designs are shown is U.S. Pat. Nos. 1,107,487, 3,289,844, 4,076,033, 4,343,710, 4,900,436, 5,037,540 and 5,045,186. However, none of these prior art patents utilize filter bag assemblies that can be readily installed and removed from a press for rapid sanitation and replacement, which filter bag assemblies have been found to be useful when the best tasting juice is desired, and which have other operational and structural deficiencies.